I. Field of the Invention
The invention is related to the fields of molecular biology, physiology, and medicine. More particularly, the invention involves compositions and methods for lowering the surface tension of a liquid-air interface with a PLUNC polypeptide or peptide fragments.
II. Background
Natural pulmonary surfactants (PS) are protein/lipid compositions that are produced naturally in the lungs and are critical to the lungs' ability to absorb oxygen. They cover the entire alveolar surface of the lungs and the terminal conducting airways leading to the alveoli. Surfactants facilitate respiration by continually modifying the surface tension of the fluid normally present within the alveoli. In the absence of sufficient surfactant, or should the surfactant degrade, the alveoli tend to collapse and the lungs do not absorb sufficient oxygen. By lowering the surface tension of the terminal conducting airways, surfactant maintains patency, i.e., keeps airways open. Loss of patency leads to obstruction of the airway and compromised pulmonary function. Human surfactants primarily contain: phospholipids, the major one being dipalmitoyl phosphatidyl-choline (DPPC), and four surfactant polypeptides, A, B, C and D with surfactant protein B (SP-B) being the most essential for respiratory function. Natural and synthetic pulmonary surfactants are commonly used to treat respiratory distress syndrome in premature infants shortly after birth.
Improved methods and compositions for achieving lower surface in pulmonary disorders, infections, and other conditions are needed.